GreenPAK speed test

Current consumption rather

The current consumption seems high, there may be some extra load on it in my test setup or something's turned on in the chip I'm not using so don't quote me on that :)

This is great news ! I use these also. i was kind of led to believe by Silego/Dialog that they could work past 20 MHz or so but no hard limit. I run a clock up to about 12 MHz maximum but this is great information to know !

Thanks !

What are its applications?

Best regards, Piotr

There have been many programmable mixed-type (analog+digital) chips over the years, but they don't seem to survive. Probably because they don't do analog or digital very well.

A small ARM with a bunch of *good* analog i/o might be interesting.

--

John Larkin         Highland Technology, Inc 

Science teaches us to doubt. 

  Claude Bernard

Mind you this is not slaving the internal PLL clock to external clock, I don't know how fast that will lock haven't tested. This is directly injecting external clock to the logic via an input pin which you can do.

Whether it works at a given speed would also depend on the complexity of the logic and I doubt a device with an asynchronous state machine can clock that fast. But for just arrays of gates I expect it would be equivalent to a discrete circuit built with VHC logic, maybe? maybe not quite that fast. Gate propagation delays on the order of 10n, not 100n, within an order of magnitude.

An interesting feature of these (haven't tried it yet) is that you can snapshot different configurations in the editor to a text file, store a snapshot in a uP memory, send it to the chip over I2C and it re-configures the array.

They're OTP in the sense that the configuration you burn it in is the one it powers up in. But once it's running the hardware can be re-configured on-the-fly by sending a set of differences over I2C.

Also some come with integrated power MOSFETs so you can roll your own one-chip converter designs.

An ARM with "good" analog is a semiconductor contradiction. Microsemi has a combination of FPGA, ARM and analog, but is it good enough? I know it's pricey, ~$50 I believe.

The Greenpak devices are a bit more like an assortment of several analog pa rts and a PLD... not even a good PLD, but they do have some timers/counters and such to augment the random logic I believe.

I think this device has legs to continue in the market place. Their niche is low cost, high volume where a $1 part can replace $1.50 of other parts.

Someone correct me if I am wrong, but their production model is that you de velop the design and they produce it for you rather than you programming th em on board or in a programmer yourself. I guess they can do it a lot chea per than you can. But you still have to burn parts for prototyping. Does that have to be in a programmer or can it be done on the board? I looked a t them a couple of times, but don't recall the details.

Ah, I read a message ahead and Bitrex says they can be programmed via I2C i t seems. Cool

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  Rick C. 

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Some of them are very interesting, e.g. the PSOC5LP family. Unfortunately, its maximum IO frequency is 33MHz and it has only one PLL.

The ARM would need to host some programmable hardware LUTs to compete with even this small mixed-type device. It escapes me why the MCUs with even ~100 LUTs either do not exist at all at the lower end or are as huge as Cyclone V/ZYNQ. If the signal frequency is ~50MHz, the MCU has simply no chance to react. One needs to deploy an FPGA, which bumps up the overengineering factor by two orders of magnitude. I see a lot of applications for a mix of an ARM and a 1kLUT MACHXO3 device.

Best regards, Piotr

Correct me if I'm wrong, but the MOSFET isn't controlled analog. It's on o r off. I looked at these to be part of a current limiter to charge a super cap and it just wouldn't do it. Or maybe it was something else. I just do n't recall. Only a small number of devices have the MOSFETs. Maybe it was a voltage limitation. I do recall somehow they've worked around the diode leaking current in the reverse direction through the parasitic diode.

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yeh, if they can do something like a STSPIN32F0 for a dollar

Interesting; what are those?

OK, but still, what can you do with two comparators and several LUTs? I understand the cost/PCB real estate saving argument, and the I2C programming is great, but let's put it aside and focus solely on the capabilities. The device is just too small to be seriously useful. Can you provide me with some clever applications?

Speaking of wish lists, I would like to have an SRAM-only FPGA directly programmable by the I2C interface from a master device. Or an MCU like that. 10 years of FLASH retention time is not enough if the device is supposed to spend 20+ years on a shelf as a spare unit. The master can keep a combined config file in an external FRAM or in a FLASH with a voting logic. One can apply this solution at most once in a design; the cost of building all the slave units like that would be prohibitive.

Best regards, Piotr

Ya pretty sure you're right, it's power-conversion oriented. It's finally a digital chip; boy it would be great to have a bunch of op-amps and passives and FETs on a chip you could wire up to do whatever. I don't think we're there yet, not at 50 cent in quantity at least.

On the project I'm working much of what the ARM is doing is moving into the FPGA. There is no reason why it can't all be done in the FPGA really. Bu t the justification is to put the alarms in "hardware" which will be easier to validate... or not. It's not me saying that, it's the lead.

99% of the functioning is measuring parameters and controlling a motor alon g with a UI. None of this is too hard for an FPGA. There may be some requ irements to track events and record a log. That would be done better in th e MCU. For now the motor control loop is all in the MCU and that is really the lion's share of the work. But a state machine is a state machine... I'm just sayin'

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  Rick C. 

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or off. I looked at these to be part of a current limiter to charge a sup ercap and it just wouldn't

just add an inductor do it as a buck, that also avoids dumping all that ene rgy in the part

l number of devices have the MOSFETs. Maybe it was a voltage limitation. I do recall somehow they've worked around the diode leaking current in the reverse direction through the parasitic diode.

back-to-back mosfets ?

I think there are some SOCs (modest FPGA plus a small ARM) in the $20 range now.

We'll be seeing smallish FPGAs with a soft RISC-V core soon too. Soft cores have been pretty bad up to now. Program space will still be a restriction, but maybe a small FPGA with a megabyte of RAM or flash and soft RISC-V would be a good product.

--

John Larkin         Highland Technology, Inc 

Science teaches us to doubt. 

  Claude Bernard

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  Rick C. 

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ptechnology.com:

.

I believe Xilinx has a soft cortex M0/M3 that is free to use in their FPGAs

I've seen several MB RAM in an SO8 package with a 133MHz QSPI interface, that might be fast enough for some code